To conduct an ocean bottom seismic survey, a cable having a plurality of pairs of electrical conductors is laid out along a survey line and connected at one end to a recording device. At spaced locations along the cable, a "takeout" is provided that enables the leader wire of a string of geophones to be electrically connected to one of the pairs of conductors inside the cable. Each pair of conductors and the phones connected to it form a data channel so that acoustic waves that are reflected upward from underground geologic structures are recorded on that channel. Once a set a data has been captured and recorded along the survey line, the cable is commonly dragged to the next survey line in preparation for another set of data. The cable may also be retrieved and redeployed in a new location to acquire another set of data.
In dragging or redeploying the cable from one survey line to the next, the seismic sensor package is commonly subjected to a number of potentially damaging obstacles on the ocean floor. In the past, the sensor, takeout, and the region of the cable in close proximity to them have been wrapped in heavy tape, and sometimes enclosed in a shrink-wrap plastic to minimize this damage. Unfortunately, this wrapping has often proved less than satisfactory, resulting in damage to the cable, the sensor, and often leading to catastrophic seawater in-leakage at the cable penetrations.
Aside from sealing the takeout, the tape and wrap applied to the cable are intended to anchor the sensor package along with its connecting leader cable. As the wrapping is damaged, the sensor package with the connecting leader cable is allowed to move freely, causing a further mechanical damage to the sensors and connecting cable.
Thus, there remains a need for an enclosure to mechanically protect and anchor the sensor package with all its connecting cable to the seismic cable. Such an enclosure should still permitting free access of seawater into the sensor held within the enclosure.